1996 Camaro Z28 Suspension Upgrades
Before I bought my '96 Z28 I had a '75 Camaro LT. I upgraded the suspension on the '75 with stiffer springs, bigger swaybars, gas charged shocks etc and it ended up handling very well. Imagine my disgust when I got in the '96 and found it to not handle as well as the 20+ year old '75! My main complaint was excessive understeer. To be frank, it plowed. And when I hit the throttle to get the tail out, it wanted to swap ends.
The first thing I did was changing the front end alignment. Thanks to idiots such as Ralph Nader, massive understeer is considered "safe", and GM dials in understeer with the alignment out of (probably justified) fear of being sued if they didn't. The main problem with the factory alignment is positive camber. Not only does it ruin handling, it also causes the tires to wear unevenly. Below are the before and after alignment settings.
| Camber (dgr) | Caster (dgr) | Toe (dgr) | |
| Stock | +0.4 | +5.0 | 0 |
| Modified | -0.4 | +3.5 | 0 |
I was trying to get a full -0.5 degree camber, but the adjustment slots were not long enough, so I had to settle for -0.4. The modified alignment above made a big difference in handling. Understeer decreased dramatically. However, bodylean was still a problem, as well as some chassis flex.
These swaybars from LG motorsports (www.lgmotorsports.com) are a lot stiffer than the
stock units. They come with special bushings and are powdercoated red. Installation is a
breeze. These swaybars really do work. Bodylean was brought well within a reasonable
level, and it balanced the car better as it decreased understeer further.
However, with the suspension stiffened up, chassis flex became noticeable. My car having T-tops didn't help either.
These subframe
connectors from LG are welded in just inside the rocker panels. The front attaches to the
front subframe, and the rear attaches to the rear trailing arm mount. This way, the front
and rear suspension is tied together and chassis flex is drastically reduced. Only problem
is that the fuel lines are routed exactly where the drivers side subframe connector has to
be welded. Further, the fuel lines are made out of plastic...
I have to admit to being nervous as I welded in these puppies. I loosened the fuel lines, and wrapped them. First I used aluminum foil, and then several layers of water-soaked rags. This did work fine and the welding was completed without incidents.
At
the same time as I installed the subframe connectors, I also installed a shock tower
brace. This ties the front shock towers together and goes over the engine.
These modifications really made the car a lot more fun to drive. Interior rattles are also prevented by the stiffening of the chassis. Although I have logged 30k miles on the car, I have no rattles or squeaks.
I
had been lusting for some 17" wheels for awhile when LG made me a great deal on these
Speedline Aliseos. These are the same wheels that came on the 1995 Pontiac Firehawk, as
well as the 1996 Firebird Comp TA. LG has since stopped selling these. As of now, the only
one I know of that offers these rims is Lingenfelter, but he wants a hefty $349 per rim. I
got a set of BFG Comp TA 275/40-ZR17 tires to go with the rims. These tires have been ok,
but I plan to replace them with Firestone SZ50 285/40-ZR17 when the BFGs wear out. They
are almost at the threadwear indicators as I write this, so check back for impressions on
the Firestones before long...
Update: I got my new Firestone SZ50s on the car. I went with the 285/40-17s and sofar I like them alot. They have slightly more straight line traction compared to the BFGs when they were new. Also, they are quiet on the highway and corner very well. Another big plus is that they fill the wheelwell up more which makes the car look much better.
I drove the
car on the Memphis Roadcourse and soon found out the stock brakes were not designed for
full out driving on a racetrack. After about 10 minutes they started fading and they soon
were so bad I could hardly stop the car. At one point I mashed the brakes and they were
just about gone. I was approaching a sharp S-curve at a much to high speed. I
double-clutched it into 2nd gear as a desperate attempt to decrease speed, but didn't get
it to slow down enough. Fortunately I only made a 180 and didn't hurt anything. However,
it convinced me to upgrade the brakes! I installed a set of these Performance Friction
Corporation Z-pads. I also changed the brake fluid to Castrol LMA. These simple upgrades
helped a lot and the next year when I drove on the Memphis track, I had plenty of
brakes. After a long race session, the pedal would be spongy, and pedal effort was high,
but the car would always stop.
With the above upgrades, the car handles well. If I'd have to complain about anything it would be 2 things:
Brake dive. With the stock springs, the car dives a lot during
hard braking. This would be fixed by installing stiffer springs, something I might do in
the future.
Incorrect weight distribution. This one is harder. With
approximately 56%/44% front to rear weight distribution it's hard to get the car perfectly
balanced. Going into a turn, it will understeer, and then with some throttle the tail
kicks out. I never realized to benefits of 50/50 weight distribution until I got my '71
Corvette. Even with the big-block in it, it still has 50.1/49.9 weight distribution. The
result of the 50/50 balance is very noticeable. Going into a turn, all 4 wheels slide. I
don't have to use the throttle to kick the tail out. At the end of the turn, I can get on
the throttle more, without going into a wide slide. There's also a lot more traction going
in a straight line.
A set of
4.10 gears are always nice... With the 0.5:1 6th gear, high speed cruising is still
comfortable. 75mph is only 2000 rpm, even with the 4.10s. The gears were installed by a
local shop that did a pretty poor job. The gears had a noticable whine during so called
'float' condition. Float is when the accelerator is almost, but not quite, released and
the drivetrain is unloaded. I had to re-adjust the gears myself and found that increasing
the backlash to 0.009" cured the noise (the shop set it at 0.006"). This shop
went out of business when most of the Vipers they supercharged blew their motors. There is
justice in the world.
As for the brand I got, Motive, they used to buy surplus GM gears. This means that you could buy $190 motive gears and get genuine $400 GM gears. However, many motive gears are made by motive, and are not as good as the repackaged GMs. The GMs are quieter and stronger. There are a few telltales that will tell motives and repackaged GMs apart.
The ringgear will be stamped "GM 7 5/8" on the GMs.
The pinion gear will have a handscribed or painted number on it on the
motives. GMs have no handscribed or painted numbers.
Rumour is Motive stopped buying surplus GM gears in the fall of '97, so the GM Motives might be getting harder to find.
This is
the Ripper, made by B&M. I really, really like this shifter. It makes for very short
throws with great feel. Installation is very easy and they go for about $170. The one for
the Camaro has a straight shaft, not curved like the one in the picture.
The TA
rear end cover/girdle is meant to strenghten the rear axle. It has adjustable bolts that
press against the carrier bearing cups. I figured with the weak 7 5/8" axle in the
camaro, it could need all the help it can get. Also, the TA cover has a drainplug, which
is nice. Since the cover does not have a magnet like the stock cover, I installed a
magnetic drainplug.
When
you have a dragster with open headers next to you it's very hard to hear your engine.
Looking at the tach really isn't what I want to do during a dragrace, so a Shift Light is
a great addition. The light is mounted on top of the dash (I put mine right next to the
a-pillar). When a pre-determined RPM is reached, a light shines into your eye and you know
it's time to shift. The activation RPM is easily changed by replacable 'pills'. The pill
can be seen in the picture. It's that little yellow thing saying '7.0'. I don't shift at
7000rpm, though. My pill says 6.0.